/Engine/Source/Runtime/Engine/Public/AnimationRuntime.h
static void BlendTwoPosesTogether ( const [FAnimationPoseData](API\Runtime\Engine\Animation\FAnimationPoseData) & SourcePoseOneData, const [FAnimationPoseData](API\Runtime\Engine\Animation\FAnimationPoseData) & SourcePoseTwoData, const float WeightOfPoseOne, [FAnimationPoseData](API\Runtime\Engine\Animation\FAnimationPoseData) & OutAnimationPoseData )